Abstract

Commercial multi-walled carbon nanotubes (CNT) were functionalized by oxidation with
HNO3, to introduce oxygen-containing surface groups, and by thermal treatments at different
temperatures for their selective removal. The obtained samples were characterized
by adsorption of N2 at -196°C, temperature-programmed desorption and determination of pH at the point
of zero charge. CNT/poly(vinylidene fluoride) composites were prepared using the above
CNT samples, with different filler fractions up to 1 wt%. It was found that oxidation
reduced composite conductivity for a given concentration, shifted the percolation
threshold to higher concentrations, and had no significant effect in the dielectric
response.